Michael Jackson would have survived an overdose of propofol if not for Dr. Conrad Murray's negligent care, a cardiologist said today in Murray's manslaughter trial.

Alon Steinberg, a cardiologist on California's Medical Board, said Murray was unethical and showed gross negligence in his treatment of the pop icon. Murray could face four years in prison if convicted of involuntary manslaughter.

"If these deviations would not have happened, Mr. Jackson would have been alive," Steinberg said.

Upon cross-examination, Steinberg said Jackson was "absolutely savable" when Murray first found the singer unresponsive. Murray told police in a taped interview that he left the singer for two minutes and found him unresponsive at around noon on June 25, 2009.

Steinberg said Murray was negligent in giving Jackson propofol to treat insomnia and failed to properly react to Jackson when the singer went into a respiratory arrest. Propofol is a powerful anesthetic typically administered in a hospital setting.

"All those deviations: giving propofol, giving propofol in an unmonitored setting without personnel, without appropriate monitoring, not being prepared, not appropriately reacting to [respiratory] arrest, not calling 911 in a timely fashion, all directly impacted his life," Steinberg said.

Steinberg called Murray's behavior bizarre. Murray did not immediately call 911 when he found the singer unresponsive in his bedroom after a night of giving the singer sedatives to help him sleep. He called Jackson's personal assistant and yelled at Jackson's chef for help. A bodyguard ultimately called 911 at 12:21 p.m.

The cardiologist reiterated that it took only four minutes for paramedics to respond to Jackson and that the singer could have gotten help far sooner.

"Every minute counts," he said.

"It's basic knowledge in America that when someone is down, you need to call 911 for help," he said. "Dr. Murray should have known that, he should have known, 'I have none of the equipment to help Mr. Jackson. I have none of the medications, I have none of the medical personnel.'"

Doctor Nader Kamangar who is an expert in sleep medicine as well as critical care said that after 4 to 5 minutes, one's brain cells start to die. As time progresses, Kamangar said brain damage becomes "irreversible, you reach a point where even if you are otherwise healthy it becomes impossible."

When Murray tried to help Jackson, he made serious mistakes, Steinberg said. Murray performed one-handed CPR on the singer while he was lying on a soft bed. The kind of respiratory arrest that Jackson suffered did not require immediate CPR, but the calling of 911, the ventilating of the singer with an bag valve mask and the use of the medicine flumazenil, Steinberg said.

Steinberg also listed several of the monitoring devices that Murray should have had on hand while administering propofol, including an EKG machine, a blood pressure cuff, oxygen and a bag valve mask. Murray had a blood pressure cuff in a closet that appeared unused and a bag valve mask was found on the floor but it was not used by Murray to ventilate the singer.

Steinberg also said additional medical personnel and a "crash cart" with certain medications should have been on hand for emergencies.

Murray's defense team says the doctor left Jackson's side for two minutes and during that time Jackson self-administered a lethal combination of propofol and the sedative lorazepam. Steinberg said that even if Jackson self-administered the drugs, that, too, would reflect Murray's gross negligence.

"You always monitor the patient in the hospital, when we give conscious sedation, the drugs are in cabinets. And we account for all the medications and we don't give an opportunity for the patient to self administer," he said.

He also said that if Murray had kept records for Jackson, he could have better assisted first responders and doctors at the UCLA Medical Center.

Murray never admitted giving Jackson propofol to emergency room doctors. He admitted administering the drug two days later in a police interview.

Doctor Kamangar said that for Murray to fail to mention Jackson's use of propofol was "unconscionable." He also said that Murray was negligent in his assessment of Jackson as an insomniac.

"Insomnia is a problem that very often is secondary…it's associated with other problems," he said.

Kamangar said that Murray should have taken a detailed sleep history of Jackson and conducted blood and lab tests to see why the singer couldn't sleep. If Jackson wasn't forthcoming about his medical history or addictions, Murray should have refused him care, Kamangar said.